Story: Floods

Page 2 – 19th-century floods

Most major rivers in New Zealand have a history of
destructive floods, and European settlers soon discovered
that floods were a recurring menace. Wellington’s first
settlers arrived at Petone in January 1840, intending to farm
the broad Hutt Valley. Less than two months after they
arrived, the Hutt River overflowed, inundating their huts and
tents. After several more floods during the next few months,
most of the settlers abandoned the Hutt Valley and moved to
Thorndon, now part of central Wellington.

In Christchurch, settlers unwittingly chose a site for the
city that was part of the constantly shifting channels of the
Waimakariri River.

Blenheim – ‘Beaver Town’

Blenheim was dubbed ‘Beaver Town’ or ‘The Beaver’ by early
surveyors – like a beaver colony built in midstream, it was
often completely swamped by the meandering Ōpawa River. The
river also acted as an overflow channel for flood water from
the Wairau River. During one period in 1893, the local
newspaper, the Daily Times, noted:

Again the town has been inundated with Opawa back-water,
and this time to a greater height than has been the case
during winter. We have now had nine floods in 11 weeks,
each of them being of sufficient size to entirely suspend
business operations for two days.1

Central Otago floods, 1863

In 1863, prospectors swarmed over the mountains of Central
Otago, camping along the streams and rivers where there was
gold. The winter that year was severe, with thick snow
blanketing the mountains. In July, warm rain deluged the
region for six days, and rain and melted snow poured into the
rivers.

Between 25 and 27 July, rivers swelled to disastrous
levels. During a single night the tributaries of the Molyneux
(now the Clutha) – the Shotover, Kawarau and Arrow rivers –
rose by 6 to 10 metres. The floods overwhelmed dozens of
miners asleep in tents and makeshift huts on the river banks
beside their claims, or even on terraces well above normal
river levels. Eight huts disappeared from a beach in the
Arrow Gorge, and by morning only one tent of many was left on
a terrace opposite the Arrow township. In the upper Shotover
River the torrent undermined a terrace, and a hut where 15
men were living collapsed into the river, and 12 drowned.

The sodden mountains gave way in landslides that sometimes
blocked the valley floors. Weeks earlier, a landslide had
dammed a stream running into the Shotover River at Māori
Point. Swollen by heavy rain, the stream burst through the
barrier on 26 July and overwhelmed a camp, killing 13
miners.

On the Arrow River, a landslide dam broke, releasing a
wall of water that swirled through the lower areas of
Arrowtown, sweeping away buildings and burying everything
beneath several metres of gravel. Most miners escaped to high
ground, but many lost all their belongings and equipment. A
few weeks later, in mid-August, the Shotover became dammed
with earth at Sands Hill. When the river broke through,
another dozen men drowned.

By the end of August more than 100 lives had been lost as
a result of the Otago floods.

Clutha floods, 1878

Although the Central Otago floods of 1863 resulted in more
deaths, the Clutha River floods of September and October 1878
caused the worst damage. Heavy rain and melting snow in the
headwaters of Lake Wānaka produced floods that lasted for
three weeks, inundating settlements and demolishing dozens of
bridges along the river. An early account described the
Clutha in flood:

[i]ts angry surface [was] strewed with dead horses and
cattle, houses, bridges, furniture, timber and farmstacks.
Some days the spring sun shone with a ghastly pleasantry on
the devastated towns, while 100 miles away more heavy rain
on the mountains was preparing still greater strength for
the flood.2

Footnotes:

Quoted in A. L. Poole, Catchment
control in New Zealand. Wellington: Water and Soil
Division, Ministry of Works and Development for the
National Water and Soil Conservation Organisation, 1933, p.
160. › Back